Attraction-repulsion among top predators following reintroduction efforts

Abstract

Much of our understanding of the effects top predators play in structuring ecological communities are from studies documenting ecological changes following the recovery or reintroduction of large carnivores. Reintroduced predators, for example, may create unanticipated competition scenarios that influence local carnivore guilds. Here, we tested whether newly released Mexican gray wolves in Chihuahua, Mexico interacted with resident pumas, as a first step in exploring potential competition between the two species. We employed GPS data and novel methods offered by MoveMine 2.0 to quantify attraction-repulsion between individual wolves and pumas during two time periods: the first when wolves were free roaming, and the second when they restricted their movements to an area around their den and rendezvous site to protect and provide for pups. In summary, attraction-repulsion analyses conducted with MoveMine provided meaningful outputs, but we would highlight the importance of fieldwork to interpret interactions and significance values calculated between pairs. We found that high attraction values resulted from mutual attraction between wolves in the same pack, between wolves and one puma they repeatedly harassed, as well as between two pumas that repeatedly exhibited social tolerance for each other. Thus, the analyses offered by MoveMine provided a powerful means of identifying interactions and assessing attraction-repulsion relevant to questions of intra- and interspecific competition, but required intimate knowledge of the species studied and the interactions between them to interpret outputs correctly.